Just from nuggets

January 12th 2013

Using Ebagoola and Palmer river nuggets we create a truly unique gold and diamond bangle.

My first task was to melt up the Ebagoola gold dust into a usable form. You can see from the photo that the dust is quite dirty and the gold is pale in colour. During melting I added some copper to enrich the colour and increase its hardness. The bangle was engraved with the golds origin and the amount of copper added to it.

Gold from the Ebagoola region usually runs at about 70% purity. This gold being unrefined would more than likely not be suitable for hand forging so I decided to lost wax cast the bangle.

Very simply lost wax casting involves creating the desired shape in wax and then suspending the wax in a medium that is not affected by high temperatures. Jewellers use a product call investment for this purpose and once the wax is set into the investment it is then placed into an oven. After sufficient heat is applied the wax dissipates and a cavity is created in the investment. The next step of the process is to inject molten gold into the cavity. Once the investment is removed the gold is revealed in the shape of the original wax.

I made this bangle in 5 sections and once they were all cast I soldered the Palmer River nuggets into place. You can see clearly the higher purity of the Palmer gold in comparison to that of the Ebagoola.

With the bangle now assembled I set 5 diamonds into each bar. A quarter of a carat of diamonds was used in total. The final step was to line and texture the top of the bangle. The variation in the colour of the Palmer and Ebagoola golds creates a lovely contrast in the finished piece. The bangle weighs 56 grams.